Air anion concentration of mangrove community in Qi'ao Island, Zhuhai City of Southern China was studied. The results showed that the diurnal variation of the negative air ion concentration in Sonneratia apetala was “V"shape, while Kandelia candel and Pongamia pinnata showed a “M冶shape. The seasonal variation of air anion concentration showed a pattern of higher in the summer and autumn, while lower in winter and spring, and the highest value occurred in summer while lowest in spring. The air anion concentration was significantly and positively related to relative humidity. In addition, K. candel community showed a higher negative ion releasing ability than S. apetala and P. pinnata. Throughout the year, the mangrove showed good air quality levels ranking between A to B.